using expanded metal in bog filter

[dozerjeep]

:) Hello, first time posting here. We are in the planning stage of our first real pond while we wait for escrow to close on our first home. We have a large rubbermaid stock tank that we plan to use as an upflow bog filter similar to this http://www.skippysstuff.com/compfiltr.html only we plan on using pea gravel instead of media pads. We still want to have a "swirl chamber" at the bottom and thought we would use expanded metal and weld on supports or use bricks to support the weight of the rock. This is what expanded metal looks like if not familar with it http://www.alibaba.com/catalog/10598542/Expanded_Metal.html

anyhow, I wasn't sure about using metal because of rust. was wondering if anyone else has used metal in pond construction. I was thinking maybe I could use plati dip coating on it? http://www.plastidip.com/consumer/index.html

thanks in advance for any advice

[Yankee Dog]

Its not going to "hurt" anything if that is what you are worried about. It will rust after a while, but depending on what grade you get it may take awhile. Just plan on replacing it when it gets too bad.

Consider lava rock instead of pea gravel. More surface area and wont clog up as badly. From experience, I can tell you the problem with either type of rock is the weight and difficulty of removal should it become necessary.

The price is right however.

yankee Dog

[GoldLenny]

They do make a stainless steel expanded metal that might last longer than the cheap stuff. Considering the time involved in breaking down the filter to replace the metal screen, I might opt to go with the more expensive stainless steel.

[pbeemer]

the plastic dip coating should give you a significant improvement in durability of the metal, but a tad expensive isn't it? if you go that way, be sure to let it cure a long time to get all the solvents out

[ohbly]

In my opinion its best to use the lightest weight media possible. The best stuff I've used is pumice gravel. The reason being that its as good at catching debris as lava rock or pea gravel, but it's much lighter and better at releasing it when you want to clean it.
As for expanded metal, I wouldn't use it because it will eventually corrode and fail.

[Lachette]

working off of the design of skippy filter, i used the usual plastic grating like they did and instead of pot scubbers, i used 9000ft of poly strapping.

http://www.packagingprice.com/forms/product_detail.cfm?categoryID=10052&productID=4147

its pretty cheap, you can sometimes get it cheaper on ebay, but some places hit you in the shipping.

[GoldLenny]

Wow... who dug up this old thread from 2007. I started reading the thread and then saw that I had replied and I knew I hadn't replied to this recently.. then I noticed the date. LOL